docs: def get_keys(self, bucket, timeout=None):
          """
          Fetch a list of keys for the bucket
          """
          bucket_type = self._get_bucket_type(bucket.bucket_type)
          url = self.key_list_path(bucket.name, bucket_type=bucket_type,
                                   timeout=timeout)
          status, _, body = self._request('GET', url)
  
          if status == 200:
              props = json.loads(bytes_to_str(body))
              return props['keys']
          else:
              raise RiakError('Error listing keys.')